Ingition switches



Dec. 19, 1967 E. CRYER IGNITION SWITCHES Filed Jan. 17, 1967 United States Patent 3,359,383 IGNITION SWITCHES Edward Cryer, Burnley, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, England Filed Jan. 17, 1967, Ser. No. 609,956

Claims priority, application Great Britain,

Feb. 17, 1966, 7,073/66 1 Claim. (Cl. 200-42) ABSTRACT OF THE DISCLOSURE Generally, this invention relates to an ignition switch for a road vehicle of the type described, comprising a fixed contact plate, an angularly movable contact plate, displaceable with a rotor from an off-position into a first position for completing an ignition circuit for the vehicle and a second position for also completing a starter circuit, and compression spring means for urging the movable contact plate in the direction of the fixed contact plate, with the compression spring means being so shaped and connected that such spring means additionally serves as a torsion spring for urging the movable plate from the second position in the direction of the first position.

This invention relates to ignition switches for use in road vehicles, of the kind including a casing having rotatably mounted therein a rotor which is movable angularly to operate the switch.

According to the invention a switch of the kind speci fied further includes a fixed contact plate, an angularly movable contact plate which is movable with the rotor from an off position into a first position in which in use it completes the ignition circuit of the vehicle, and a second position in which it also completes the starter circuit of the vehicle, and a compression spring urging the movable contact plate towards the fixed contact plate, said spring being so shaped and connected that it also acts as a torsion spring urging the movable plate from the second position towards the first position.

One example of the present invention is illustrated in the accompanying drawings wherein FIGURE 1 is a sectional side view of an ignition switch, FIGURE 2 is a sectional view on the line 22 in FIGURE 1 and FIG- URE 3 is an end view of the switching in the direction of arrow A in FIGURE 1.

The ignition switch illustrated in the drawings is of the key-operated type having four operative positions, an oil position in which the key may be removed from the switch, a first position, achieved by turning the key clockwise, in which the ignition and auxiliary circuits of a road vehicle are energised, a second position, achieved by turning the key further in a clockwise direction, in which the starter motor circuit is energised in addition to the ignition circuit, and a third position, achieved by turning the key counter clockwise from the off position, in which only the auxiliary circuits of the vehicle are energised.

Referring to the drawings, there is provided a cylindrical casing 11 which is stepped to provide a shoulder 18 and is closed at its wider end by a contact board 14. Rotatable within the narrower cylindrical part 12 of the casing 11 is the core (not shown) of a cylinder lock, the part 12 of the casing 11 constituting the barrel of the lock. Within the wider part 15 of the casing 11 is a rotor 16, rotatably supported at one end in the contact board 14 and secured at its other end to the core of the lock for rotation therewith.

The rotor 16 is moulded in a synthetic resin material and is formed with a head 17 of substantially elliptical configuration (FIGURE 2). The head 17 abuts against the shoulder 18 of the casing 11, and extending axially from the head is a hollow substantially cylindrical shank 19, formed with a pair of diametrically opposite longitudinally extending flats (not shown) and a longitudinally extending slot 22 the end of the shank 19' being rotatably supported in a hole 21 formed in the contact board 14.

Surrounding the shank 19 is an annular contact plate 23 provided with projections 24, the hole in the plate 23 being shaped complementarily to the shank 19 so that the plate 23 rotates therewith.

Associated with the board 14 are four contacts 26, 27,

28, 29 each of which incorporates one or more terminal blades positioned externally of the plate 14 for connection to external circuits, and a contact portion on the interior of the plate, the contact portions extending into holes in an insulating plate 35 over which the projections 24 move.

The contact plate 23 is urged towards the contact board 14 by a spring 36, one free end 36a of which is engaged in the slot 22 in the shank 19, and the other free end 36b of which extends towards the inner wall of the casing 11.

The rotor 16 is provided with an axially extending bore 38 of non circular cross section with which is engaged a complementarily shaped spigot which extends from the core of the cylinder lock. By virtue of this engagement the rotor 16 is rotatable with the core of the lock. In the head 17 is a radial bore 39 containing a ball 41 which is urged by a spring 42 into engagement with an arcuate cam track 43 on the casing 11.

The cam track 43 comprises three angularly spaced depressions 44, 45, 46. When the switch is in its off position the ball 41 is engaged with the depression 45 of the cam track 43 and the projections 24 of the contact plate 23 engage with the insulating member 35.

If it is required to energise the auxiliary circuit of the vehicle an ignition key is inserted into the core of the cylinder lock and rotated in a counter clockwise direction.

Since the core of the lock, the rotor 16 and the contact plate 23 are not rotatable relatively to one another, angular movement of the key results in angular movement of the plate 23 with respect to the contacts on the contact board 14. By turning the key in a counter clockwise direction the plate 23 is moved to a position in which it bridges the input and auxiliary contacts and so completes the auxiliary circuit. When the plate 23 is in this position the ball 41 engages the depression 44 which prevents accidental rotation of the key and consequently the plate 23. By virtue of the engagement of the end 36a of the spring 36 with the slot 22 in the shank 19, the spring 36 is rotated with the shank 19.

To complete the ignition circuit of the vehicle the key is turned in a clockwise direction, the ball 41 engages the depression 46 and the plate 23 bridges the input ignition and auxiliary contacts thereby completing the ignition and auxiliary circuits. The end 36b of the spring 36 now engages a lug 37 formed as part of the cam track 43. To energise the starter motor of the vehicle the key is rotated further in a clockwise direction which forces the ball 41 to ride up the ramp 47 and causes the contact plate 23 to bridge the input and starter contacts while maintaining the bridge between the input and ignition contacts. However since the end 36b of the spring 36 is engaged with the lug 37, such further rotation of the key in a clockwise direction causes the spring to be twisted, so that if the key is now released the spring 36, now acting as a torsion spring, will return the switch to its first position in which the ball 41 engages the depression 46 and the ignition circuit is still completed but the starter motor circuit broken.

Patented Dec. 19, 1967 The part 12 of the casing 11 is externally screw threaded to facilitate mounting of the switch on the dashboard or bulkhead of a road vehicle.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

An ignition switch for use in a road vehicle, comprising in combination a casing, a rotor rotatably mounted in said casing, a fixed contact plate secured to said casing, a second contact plate axially movable with respect to said rotor, a compression spring urging said second contact plate into engagement with said fixed contact plate, means coupling said second contact plate to said rotor for angular movement therewith from an oif position into a first position in which the second contact plate co-operates with the first contact plate to complete the ignition circuit of the vehicle, and a second position in which the second contact plate co-operates with the fixed contact plate to complete both the ignition circuit and the starter circuit of the vehicle, said compression spring having one end thereof coupled to a part of the switch which moves angularly, and the other end of said compression spring being engageable with the casing when the second contact plate is moved from said first position to said second position, whereby movement of said second plate from said first position to said second position stresses said compression spring in torsion so that the spring urges the second contact plate towards said first position.

References Cited UNITED STATES PATENTS 1,713,142 5/1929 Noruiel 200-44 ROBERT K. SCHAEFER, Primary Examiner.

Hi HOHAUSER, Assistant Examiner. 

